1. Field of the Invention
This invention generally relates to surveillance systems. Specifically, the invention relates to a video-based surveillance system that can be used, for example, to detect when a person falls or gets up.
2. Related Art
Some state-of-the-art intelligent video surveillance (IVS) system can perform content analysis on frames generated by surveillance cameras. Based on user-defined rules or policies, IVS systems may be able to automatically detect events of interest and potential threats by detecting, tracking and classifying the targets in the scene. For most IVS applications the overall tracking of objects is sufficient: that already enables e.g. detecting when an object enters a restricted area, or when an object is left behind or taken away. In other applications, however, some further granularity is needed. The detection of change in posture, for example, when a person falls or gets up, is an example of this. Detecting such events is important in a wide range of applications, including dispatching help quickly, especially in hospitals, nursing homes, or in the homes of the sick or the elderly; for liability reduction; or in security applications when guarding people.